In recent years, various computer simulations using a finite element method have been conducted. In these simulations, a finite element model is created by discretizing an object to be analyzed using a finite number of elements that can be handled by a computer. The finite element model is inputted a characteristic representing the stiffness and viscosity thereof. In the computer simulation using the finite element method, displacement of each node is calculated based on the predetermined deformation condition or the like.
In recent years, a computer simulation using the finite element method is used in not only a mechanical structure but also in a development of a rubber material. For example, in order to streamline the development of a filler for reinforcing rubber, the following Patent Documents 1 and 2 have proposed a method for creating a finite element model of a filler compounded rubber including the filler dispersed in the matrix rubber with a computer.
In Patent Document 1 and Patent Document 2, the respective portions occupied by the matrix rubber and the filler, for example, are identified based on a microscopic cross-section photograph of the filler compounded rubber. The respective portions, for example, are modeled into a matrix rubber model and a filler model using two-dimensional elements such as a triangle or quadrilateral.    Patent document 1: Japanese Unexamined Patent Application Publication No. 2012-185733    Patent document 2: Japanese Unexamined Patent Application Publication No. 2012-198654